1. Field of the Invention
The present invention relates to a method for manufacturing a pattern of a light shielding layer and a pattern forming body of a light shielding layer obtained by the method, more particularly, relates to a method for manufacturing a pattern of a light shielding layer, capable of manufacturing a highly sensitive and highly precise pattern of a light shielding layer and capable of manufacturing a pattern of a light shielding layer in a short period of time, and a pattern forming body of a light shielding layer.
2. Description of the Related Art
Recently, as flat displays, monochrome or color liquid crystal displays attract attention. Modes of liquid crystal displays are classified to an active matrix mode and a simple matrix mode, for controlling three primary colors and in both modes, color filters are used. Liquid crystal displays have constitution of three primary colors (R, G, B) of pixel parts, and perform color display by controlling transmission of each color of the three primary colors by electrical switching of a liquid crystal.
This color filter is constituted by forming each coloring layer, protective layer, and transparent electrode layer on a transparent substrate. To enhance a color development effect and display contrast, a pattern having a light shielding property (light shielding layer pattern, or black matrix) at interface parts between pixels of R, G and B of a coloring layer is formed. In liquid crystal displays of an active matrix mode, a thin film transistor (TFT) is used as a switching element, it is necessary to control light leakage electric current by outer light. Therefore, a high light shielding property is required for a black matrix.
Conventionally, the black matrix includes those obtained by relief formation by photo-etching of a chromium thin film formed by vapor deposition, sputtering or the like, those obtained by dyeing a hydrophilic resin relief, those obtained by relief formation using photosensitive liquid containing a black pigment dispersed, those formed by electro-depositing a black electro-deposition paint, those formed by printing, and the like.
However, though the above-mentioned black matrix obtained by relief formation by photo-etching of a chromium thin film show high dimensional precision because of use of a photo-process, a vacuum film forming process such as vapor deposition, sputtering and the like is necessary and its production process is complicated, therefore, production cost thereof is high, and further, to enhance display contrast under strong outer light, reflectance at the observed side is required to be suppressed, causing a necessity to conduct sputtering and the like of low reflection chromium requiring higher production cost. The above-mentioned method using a photosensitive resist containing a black dye and pigment dispersed previously gives low production cost, however, has a problem that a photo process tends to be insufficient since a photosensitive resist is black, consequently, when dimension precision is required, it is difficult to obtain a sufficient light shielding property, meaning that a black matrix of high quality is not obtained. Further, in the above-mentioned black matrix formation by a printing method, though it is possible to reduce production cost, a problem arises when high dimension precision is required.
On the other hand, for solving such problems, the present inventors have investigated a method for manufacturing a pattern, in which a pattern is formed by using a substance which a property is changed by the action of a photocatalyst, and the like. However, in conventional technologies, large exposing amount is necessary for changing a property, therefore, a treatment time is made longer, being an industrial problem. Further, longer treatment time is a cause for reduction in resolution.